Spray gun



Patented Jan. 21, 1930 UNITED STATES PATENT OFFICE WILLIAM R. BROWN, OF CHICAGO, ILLINOIS SPRAY GUN Application led February 5, 192'?.

device of this character particularly suitable for use in places like garages Where air pressure is generally available but at widely diiiferent pressures.

An object of the invention is to provide self-regulating means which, regardless of the fact that a higher than necessary air pressure may be delivered to the device, the pressure will automatically be cut down in the device so that the same operates at some predetermined lower pressure. Another object of the invention is to provide adjustable means for determining the pressure utilized in the device, such as ten, fifteen or twenty pounds, even though the source of air pressure may be very much higher.

The objects of the invention are accomplished by a construction such as is shown in the drawings, wherein,-

Fig. 1 is a longitudinal, sectional view of the improved spray device;

Fig. 2 is a plan view; and

Fig. 3 is a sectional detail taken on the line 3--3 of Fig. 1.

The principal features of the construction illustrated are the customary atomizing arrangement wherein two nozzles have their outlet ends close together and in angular relationship, one of said nozzles serving to deliver the fluid to be sprayed and the other nozzle serving to deliver the atomizing medium, such as air under pressure. The latter nozzle is controlled by a valve which may be set by a trigger to its open position, the full stroke of the trigger being regulated byan adjustable stop, but the opening of the valve under the action of the trigger is through a resilient connection which is subject to the pressure of the air delivered to the device so that the valve will be returned more or less towards its closed position, thereby cutting down the pressure to the predetermined amount determined by the adjustable sto The construction as shown in the drawing comprises the container l for holding the Serial No. 166,240.

iuid to be sprayed and the handle 2 secured thereto. Two nozzles 3 and e have their outlet ends close together and in angular relationship, the nozzle 3 serving to deliver the fluid to be sprayed and the nozzle 4 serving to deliver the atomizing medium such as air pressure. The nozzle 3 is vertically adjustable as by the nut 5 and held by spring 6.

The container has a screw cap 7 which has a valve housing 8 secured thereto as by the screws 9.

The atomizing medium such as air under pressure is delivered through the conduit 10 to the cylinder 11 within the housing 8. A second cylinder 12 communicates with the nozzle 1 through the passageway 13.

A pair of reciprocating members 14 and 15 are disposed within the cylinders 11 and 12 respectively and are so formed that a passageway 16 is provided between themselves and their cylinder walls. A helical spring 17 is interposed between the end of the cylinder 11 and the reciprocating member 1-1.

The cylinders communicate with each other through the passageway 1S and a valve 19 having a stem 2O is operatively connected with the reciprocating member 15.

A plunger 21 bearing against the spring 22, is longitudinally movable within the housing 8, through the trigger 23, pivotally connected at 24 to the handle supporting member 25. The plunger 21 is provided with an adjusting nut 26 for determining its throw.

A pressure actuated diaphragm 27 is interposed between the reciprocating member 15 and the end 2S ot the spring tensioned plunger 21.

In the operation of this device the adjustment of nut 26 determines the pressure utilized for atomizing purposes. For example, this nut may be set for an operating pressure of twenty pounds. The pressure in the supply conduit may, for example, be sixty, seventy, or eighty pounds. Trigger 23 is drawn toward the handle 2 until nut 26 engages the end of the bearing for plunger 21. Through the plunger 21 and connections with the valve 19 the latter is pushed away from its seat, admitting air under pressure to the passageway 13 of the atomizer at a rate determined by the size of the opening at valve 19, and building up a pressure in the passageway 13 as controlled by the restriction at nozzle 4. This pressure acts upon diaphragm 27, pushing it against the action of spring 22, and allowing spring 17 to move the valve toward its seat until the opposed forces on the valve are equal. The setting of the valve then corresponds to the original setting of nut 26, insuring the desired predetermined drop in pressure.

While but one specific embodiment of this invention is shown in the accompanying drawings, it will be understood that numerous details of the construction shown may be altered or omitted without departing from the spirit of this invention, as defined by the following claims.

I claim:

1. In a hand spray gun, having a handle for holding the gun, a valve between the supply ressure and its outlet, and means for control ing and regulating the atomizing pressure comprising finger controlled means for opening said valve and pressure actuated means operable by the atomizing pressure for variably closing the valve, said finger controlled means being mounted convenient to the handle so that it can be controlled by the same hand which holds the gun.

2. In a hand spray gun having a handle for holding the same, a valve between the supply pressure and its outlet, and means for controlling and regulating the atomizing pressure comprising finger operable means adjacent the handle and yieldably connected to the valve for opening the same and pressure actuated means operable by the atomizing pressure for closing the valve when the pressure rises above a pressure determined by the first mentioned means.

3. In a hand device for utilizing fluid at low working pressures from a variable high pressure source, a housing having an outlet nozzle and a fluid inlet, a check valve between the inlet and the nozzle, a diaphragm subjected to the pressure at the nozzle, a plunger lnterposed between the diaphragm and the valve, a load spring bearing on the outer surface of the diaphragm, a handle for holding the device attached to the housing, and a trigger mounted on the handle for applying pressure to said spring so that'the valve may be opened and the outlet pressure varied at will b the same hand which holds the device.

4:. n a hand device of the class described, a housing, means mounted in the housing for controlling the outlet fluid pressure, said means comprising a pressure reducing and regulating valve having a load spring for governing the reduced pressure, a handle mounted on the housing for holding the device and a trigger adjacent the handle connted to control the tension ofthe spring so that the working pressure may beturned on ary, 1927.

WILLIAM R. BROWN. 

